| Rådhusvegen 34 AS | Real estate | 2025 |
| S. Narvestad AS | Real estate | 2016 |
| Safi Consulting AS | Professional & scientific | 2025 |
| Safir Data AS | Information & communication | 1994 |
| Safir Holding AS | Information & communication | 2005 |
| Safir Web AS | Information & communication | 2011 |
| Sanne Asset Management AS | Administrative & support | 2024 |
| Secpro AS | Other services | 2012 |
| Securityproducts AS | Wholesale & retail | 2005 |
| SG Trafikkskole AS | Education | 2025 |
| Sir Jensen Holding AS | | 2024 |
| SK Hadeland Da | Administrative & support | 2024 |
| Skandinavisk Radoninvest AS | Professional & scientific | 2022 |
| Skandiwood AS | Wholesale & retail | 2023 |
| Skapalen Drift & Utleie AS | Transport & logistics | 2023 |
| Smedsrudbrovolden Eiendom AS | Real estate | 2019 |
| Smiesh AS | | 2024 |
| Sportygården AS | Arts & recreation | 2023 |
| Stabbursbakeriet Da | Manufacturing | 1998 |
| Stensvold & Larsen Invest AS | Real estate | 2024 |
| Storvoll Maskin AS | Administrative & support | 2025 |
| Strandås AS | | 2025 |
| Stølen Holding AS | Wholesale & retail | 2016 |
| Stølen-Eiendom AS | Real estate | 2016 |
| Sørbråten Blikk Og Ventilasjon AS | Construction | 2006 |
| Sørbråten Eiendom AS | Real estate | 2013 |
| Sørvangsbakken 1 Eiendom AS | Real estate | 2015 |
| T Andersen Eiendom AS | Real estate | 2017 |
| T-D Eiendom AS | Real estate | 2019 |
| TD2E Holding AS | Real estate | 2014 |
| Technology With a Heart AS | Information & communication | 2015 |
| Terje's Transport Og Graving AS | Construction | 2022 |
| Tero Anlegg AS | Construction | 1991 |
| Teslow Gruppen AS | Agriculture & fishing | 2025 |
| TH Anlegg AS | Construction | 2005 |
| Tjernslien AS | | 2011 |
| Tokra Holding AS | Construction | 2018 |
| Tordenskjolds Gate 13-15 AS | Real estate | 2021 |
| Trainpoint Norway AS | Administrative & support | 2015 |
| Tram AS | Financial services | 2018 |
| Trond Bekken Strøm AS | | 2018 |
| Trond Jenserud AS | | 2020 |
| Trox Auranor AS | Manufacturing | 1996 |
| Trulserudenga Barnehage SA | Education | 2001 |
| Tveter Dagligvare AS | Wholesale & retail | 2023 |
| VB Eiendom AS | Real estate | 2001 |
| Vestås Varden Holding Og Eiendom AS | Real estate | 2024 |
| Vigga Bygg AS | Construction | 1987 |
| Vigga Kraft Da | Energy | 2008 |
| Vika Bil AS | Wholesale & retail | 2015 |
| Økonomisjekken AS | Professional & scientific | 2021 |